| /* |
| * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package build.tools.classfile; |
| |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.nio.file.Paths; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.Set; |
| import java.util.HashSet; |
| |
| import com.sun.tools.classfile.AccessFlags; |
| import com.sun.tools.classfile.Attributes; |
| import com.sun.tools.classfile.ClassFile; |
| import com.sun.tools.classfile.ClassWriter; |
| import com.sun.tools.classfile.ConstantPool; |
| import com.sun.tools.classfile.Field; |
| import com.sun.tools.classfile.Method; |
| |
| public class RemoveMethods { |
| |
| public static void main(String[] args) throws Exception { |
| if (args.length < 2) { |
| System.err.println("Usage: java RemoveMethods classfile output [method...]"); |
| System.exit(-1); |
| } |
| |
| // class file to read |
| Path input = Paths.get(args[0]); |
| |
| // class file to write, if directory then use the name of the input |
| Path output = Paths.get(args[1]); |
| if (Files.isDirectory(output)) |
| output = output.resolve(input.getFileName()); |
| |
| // the methods to remove |
| Set<String> methodsToRemove = new HashSet<>(); |
| int i = 2; |
| while (i < args.length) |
| methodsToRemove.add(args[i++]); |
| |
| // read class file |
| ClassFile cf; |
| try (InputStream in = Files.newInputStream(input)) { |
| cf = ClassFile.read(in); |
| } |
| |
| final int magic = cf.magic; |
| final int major_version = cf.major_version; |
| final int minor_version = cf.minor_version; |
| final ConstantPool cp = cf.constant_pool; |
| final AccessFlags access_flags = cf.access_flags; |
| final int this_class = cf.this_class; |
| final int super_class = cf.super_class; |
| final int[] interfaces = cf.interfaces; |
| final Field[] fields = cf.fields; |
| final Attributes class_attrs = cf.attributes; |
| |
| // remove the requested methods, no signature check at this time |
| Method[] methods = cf.methods; |
| i = 0; |
| while (i < methods.length) { |
| Method m = methods[i]; |
| String name = m.getName(cp); |
| if (methodsToRemove.contains(name)) { |
| int len = methods.length; |
| Method[] newMethods = new Method[len-1]; |
| if (i > 0) |
| System.arraycopy(methods, 0, newMethods, 0, i); |
| int after = methods.length - i - 1; |
| if (after > 0) |
| System.arraycopy(methods, i+1, newMethods, i, after); |
| methods = newMethods; |
| String paramTypes = m.descriptor.getParameterTypes(cp); |
| System.out.format("Removed method %s%s from %s%n", |
| name, paramTypes, cf.getName()); |
| continue; |
| } |
| i++; |
| } |
| |
| // TBD, prune constant pool of entries that are no longer referenced |
| |
| // re-write class file |
| cf = new ClassFile(magic, minor_version, major_version, cp, access_flags, |
| this_class, super_class, interfaces, fields, methods, class_attrs); |
| try (OutputStream out = Files.newOutputStream(output)) { |
| new ClassWriter().write(cf, out); |
| } |
| } |
| } |